The effects of Ca2+ and Mg2+ on the major gelatinase activities present in the sea urchin embryo.
We have examined the effects of Ca2+ and Mg2+ on the activities of the two most prominent gelatinases present in the developing sea urchin embryo. The EDTA-inhibited 41 kDa gelatinase was variously reactivated by concentrations of Mg2+ at or below 15 mM while the EDTA-inhibited 87 kDa gelatinase could not be reactivated by Mg2+. Magnesium partially inhibited the activities of both gelatinases and Ca2+ was protective against these inhibitory effects. In competition studies Mg2+ was shown to complete with Ca2+ for binding to the gelatinase. These results demonstrate competition between Ca2+ and Mg2+ for binding to and regulating the activities of these gelatinases in a marine environment which contains 10 mM Ca2+ and 50 mM Mg2+.
Robinson
J J
JJ
Department of Biochemistry, Memorial University of Newfoundland, St. John's, Canada. JOHNRO@MORGAN.UCS.MUN.CA
Mayne
J
J
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018093:Gelatinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology*; D008970:Molecular Weight; D012617:Sea Urchins / Q000187:drug effects / Q000196:embryology / Q000201:enzymology*
D004791:Enzyme Inhibitors; D018093:Gelatinases; D008274:Magnesium; D002118:Calcium